<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			p{
				width:250px;
				background:#ccc;
			}
			.first{
				/*border-top-color:red;
				border-top-width:1px;
				border-top-style:solid;
				border-right-color:blue;
				border-right-width:2px;
				border-right-style:dashed;
				border-bottom-color:#ccc;
				border-bottom-width:4px;
				border-bottom-style:outset;
				border-left-color:pink;
				border-left-width:6px;
				border-left-style:double;*/
				
				/*border-top:1px solid red;
				border-bottom:2px dashed blue;*/
				
				/*border-color:red blue;
				border-width:2px;
				border-style:solid dashed dotted;*/
				
				border:5px solid red;
				padding:20px;
				margin:10px;
			}
			
			.second{
				/*padding-top:5px;
				padding-left:3px;
				padding-bottom:10px;
				padding-right:8px;*/
				padding:5px;
			}
			.third{
				/*margin-top:50px;
				margin-letd:30px;*/
				/*margin:10px 20px;*/
				
				/*
				元素的居中
				*/
			   /*1.块级元素水平居中*/
			   margin:5px auto;
			   /*2.文本水平居中*/
			   text-align:center;
			   /*3.垂直居中：将height和line-height设置为相同*/
			   height：100px;
			   line-height:100px;
			}
		</style>
	</head>
	<body>
		<p class="first">welcome to html</p>
		<p class="second">welcome to html</p>
		<p class="third">welcome to html</p>
	</body>
</html>
